The in relates to electric motors.
The invention relates more particularly to small permanent magnet direct current motors. Such motor often require, especially where used in automotive applications, electromagnetic interference suppression to prevent problems with radio receiver receptions and more importantly interference with the satisfactory operation of control integrated circuits concerned with the safe running of the vehicle. Often there are statutory regulations applicable to all equipment used in automotive and other environments to reduce electromagnetic interference or noise and which must be met by any motors used in appropriate applications governed by such regulations.
Suppression circuits are therefore provided to meet the regulations and are used together with the motor as part of the supply or control circuits of the motor. The suppression circuits normally include a number of different discrete electrical components which must be electrically connected together in a manner in which the electrical connections between the components themselves are not prone to become a source of noise. Also the electrical connections must preferably be reliably reproducible during mass-production assembly and yet as cheap as possible.